Q. I'm a 28-year-old man with a good physique, except for one problem -- a "sunken" chest. What is the best exercise to get rid of this problem? I have access to the full range of gym equipment, but no amount of pumping iron seems to help.

A. It sounds like you have funnel chest, or what doctors call pectus excavatum, from the Latin words for hollowed-out chest. This condition results from a problem in the way your chest develops. The cartilage connecting your rib cage to your breastbone doesn't develop properly, and your breastbone is sunken as a result.

Exercise and weightlifting will give you extra muscular padding that may make this chest deformity less pronounced, but they may also make it more noticeable. The only effective treatment for pectus excavatum is surgery, which repositions the breastbone forward. In one type of operation, a surgeon actually turns your breastbone over, so that the inner ridge now faces outward.

Funnel chest is mainly a cosmetic problem. It hardly ever interferes with the work of the heart or lungs underneath. Because corrective surgery can be extensive, and because the condition can occasionally recur after an operation, you should be sure the deformity is severe enough to warrant an operation.

A related condition is pectus carinatum, meaning keeled chest (like the keel of a boat), also known as pigeon chest, in which the breastbone is positioned too far forward. Mainly a cosmetic deformity, this problem can also be treated by surgery if it's severe.

Q. I recently heard great claims being made about a drug called acetylcholine in the treatment of Alzheimer's disease, though the report said it could be five to 10 years before it might be put into general use. What is the hope that this will prove effective? For you to address this devastating disease would lend a much-needed hand to those of us who find ourselves in the role of caretaker, where just coping seems an impossible task.

A. I think I can be more helpful to you by talking about ways of coping than discussing uncertain remedies for this terrible affliction that slowly robs people of their mental function.

A preliminary study did show a small amount of temporary benefit when Alzheimer's patients were treated with acetylcholine, a chemical important in brain function. But this drug had to be given directly into the brain through a small tube in the skull, and the results, though promising, were not spectacular. It's clear that much more research needs to be done before we have a good, reliable treatment for Alzheimer's disease.

In the meantime, the burden of caring for most people with Alzheimer's disease falls to their families. In a previous column on Alzheimer's disease, I recommended a book, "The 36-Hour Day," by Drs. Nancy Mace and Peter Rabins. This book contains a wealth of practical information on how to care for and cope with victims of this devastating illness. I also recommended joining one of the two local chapters of the Alzheimer's Disease and Related Disorders Association, located in Bethesda (652-6446) and Falls Church (534-8446).

A new resource I recently came across is the book "Home Health Care" by Jo-Ann Friedman. It's a superb reference that gives step-by-step advice about caring for loved ones at home, whatever their affliction. It tells how to make the best use of home health services (nursing, health aides, social workers), how to prepare your house for home care, and how to deal with the day-to-day activities of nutrition, exercise, and personal hygiene.

"Home Health Care" gives tips on pain control, prevention of bedsores and care of the terminally ill. It discusses many common health problems that affect the elderly, and contains a large directory of resources for further information. Although some of the chapters would not apply to all people, much of the information is basic to the care of debilitated persons in their own homes. I recommend it to all caretakers as one way to keep coping from becoming an impossible task.

Q. Does running cause arthritis? I've wondered whether all the jogging I do will eventually give me arthritis in my knees.

A. Not all the evidence is in, but some doctors have concluded that regular running neither helps nor hurts your leg joints.

One study compared 17 male runners (average age 56) with 18 nonrunners. Half the runners were marathoners, and all ran an average of 28 miles a week for 12 years.

Runners and nonrunners had about the same amount of pain in the hips, knees, ankles and feet. Both groups also had similar X-ray changes, the kind that occur with degenerative arthritis. Also known as osteoarthritis, this is the most common type of arthritis, often thought to be caused by "wear and tear" and the effects of aging.

While running didn't seem to protect against getting degenerative arthritis, it didn't seem to hasten its development, either.

Another study of 41 long-distance runners between 50 and 72 years of age showed that runners had spinal bones 40 percent more dense than those of nonrunners. This effect, the opposite of bone-thinning osteoporosis, shows the potential protective action exercise has against fractures in older age. Although women runners in this study had more X-ray evidence of mild degenerative arthritis, they had no more symptoms of arthritis than nonrunners.

Other studies, however, have found certain patterns of arthritis in athletes and workers -- spine, knee and elbow arthritis in wrestlers, wrist arthritis in boxers, and shoulder and elbow arthritis in baseball pitchers and pneumatic drill operators.

Many people with arthritis have pain after exercising their arthritic joints, but these studies of runners suggest that this doesn't necessarily imply further joint damage. As a rule, it's best to avoid exercising to the point of pain. Jay Siwek, a family physician from Georgetown University, practices at the Fort Lincoln Family Medicine Center in Northeast Washington. Send questions to Consultation, Health Section, The Washington Post, 1150 15th St. NW, Washington, D.C. 20071. Questions cannot be answered individually.